The couple, who earlier said they would face losing their family home if they lost cost orders in the case, are understood to have failed to stump up with the money

They declined to comment for this story.

Donna Baluskas now has effectively no defence to the defamation suit and Miguel has a greatly trimmed-down defence. He is claiming the defence of justification.

The $1 million case is due back in court on Thursday in the District Court in Southport before trial Judge Catherine Muir to finalise plans for the three week judge-only hearing, set to start on October 8.

Parent Donna Baluskas. Picture: Adam Head

Meanwhile last week Facebook, a counselling service from Beaudesert, web-petition company Change.org and the state Education Department were dragged into the stoush, with the District Court issuing formal demands forcing the companies to hand over confidential documents related to children named in the case to Mrs Brose's lawyers.

The notices are part of pre-trial discovery related to key issues in dispute.

Already one parent sued for defamation, school lollipop lady Trudie Arnold, from Canungra, has filed for bankruptcy.

When she launched the case more than three years ago, Mrs Brose sued eight parents, but she settled against three out of court.

Donna and Miguel Baluskas were sued over comments they made on Facebook and a Change.org petition in March 2016, two years after their son Harrison, then aged 12, was expelled by Mrs Brose from TMSHS.

Mrs Brose is alleged to have told Donna Baluskas that Harrison was "a sexual predator" and that she and her husband "had blinkers on" and were "in denial" after he said "show me your dick" to another student on the school bus in February 2014, according to court documents.

Mrs Baluskas is alleged to have called Mrs Brose an "evil, nasty, horrible women (SIC)" on Facebook.

Grocery merchandiser and mother-of-three Laura Lawson, 49, from Coomera has pleaded the defence of justification to imputations that her Facebook posts implied Mrs Brose "is petty, small minded and spiteful in her enforcement of school rules".

Mrs Brose suspended Mrs Lawson's middle son from TMSHS because another student wrote an "unsavoury phrase" on his fibreglass arm cast, and her eldest son was sent home because he had an eyebrow piercing, court documents state.

Parent Laura Lawson

Parent and aged care nurse Charmaine Proudlock was sued over comments she posted on Facebook in March 2016 after daughter Jordyn was expelled in 2014.